This proposal describes a Center Core and four related research projects dealing with salient health and psychosocial problems of the aged. Specific aims are: 1) develop a Center Core as a focus for institutional liaison and research collaboration and for technical and administrative support. 2) Conduct four associated research projects in clinical geriatrics. The Center Core will be staffed by a senior physician as Project Director who has extensive clinical, research and administrative experience related to aging, an internist as Center Director engaged in research in pulmonary disease, and Administrative Coordinator with training and experience in community organization and academic administration, and a Nurse Coordinator with clinical and research experience related to aging. The Center Core will staff three committees: a Liaison Committee, consisting of representatives of the collaborating institutions, a Scientific Advisory Committee of local and national experts, reponsible for scientific review and research development, and an Administrative Committee to operate the program and manage recruitment and follow-up of research subjects. All studies require recruitment or follow-up of elderly persons. Project 1 establishes a framework of the natural history of a defined elderly population; the other studies explore in depth specific common clinical problems influencing their functional dependency. The project is a longitudinal interview survey of levels of dependency, in terms of physical and mental health and function, and changes in these conditions over a 9 year period. Survivors will be reinterviewed, and a subsample of 120 will be examined. Specific hypotheses are to be tested. Project 2 will study normal older volunteers and patients aged 50-80 years with chronic pain and affective illness in order to improve the identification of depression and to distinguish associated symptoms from those atributable to chronic pain. Project 3 will make comparisons of young and old volunteer subjects in terms of respiratory muscle strength, endurance, and coordination. Involuntary and voluntary mechanisms which could affect the control of respiratory muscles will be studied. The project will examine age differences in response to strength and endurance training and effects on specific aspects of respiratory muscle control. Project 4 will determine whether airway and autonomic reactivity, which are important components of chronic lung disease, are altered with aging, and whether these two changes are correlated. Healthy adults aged 20-80+ will be studied using established in vivo and in vitro techniques. Findings could lead directly to changes in treatment and management of the elderly.